Are Water Changes Actually Necessary?

[GuppyGirl1230]

So far, four people have voted that they do water changes on a timeline...

But nobody has posted any explanation as to why.

This sounds, to me, like people are stressing their fish needlessly.

If not, then we need to hear the actual reason for it.

If someone finds that their nitrates build up, in a shallow gravel tank, with such regularity that they can reliably change the water each week, and they don't care to try some better means of reducing nitrates...that at least makes sense. But, really, it falls into the category of "only change when conditions require", because they took the time and effort to learn the schedule of those conditions, in their specific tank.

People who simply change the water every day/week, because someone told them to...is that doing anything but giving the fish needless stress?

I do water changes weekly or bi-weekly depending on what my water tests say. One reason to do them is to reduce the total dissolved solids, another reason is to get rid of the growth hormones in the water that come from growing fish. These hormones reduce growth in the fish if there are too many in the water. I also have plastic plants, so I have to remove wastes periodically. Even my scavengers (cories, shrimp and snails) do not remove all waste, and create some themselves.

Once I convert my tanks to planted instead of plastic, I doubt I will be changing the water more than once a month. But I will still be changing it.

And, maybe it is just me, but I feel like the fish need fresh water... I just feel like it is healthier for them.

Maybe this is like the salt or no salt thing, everyone has a different opinion, method, or theory on it. I think you have to decide for yourself, after all they are your tanks, and your fish.... I would still do regular water changes though!!

Maribeth

 

[drunkenmastera]

In wild life, they get constant water change with moving water. In order to keep them close to their habitat, water change is necessary.

 

[GoldLenny]

I see that Kaz was likely a troll and started this thread and then left after 49 replies since he wasn't getting any affirmation for his laziness... but I thought I'd reply to a few of his posts anyhow just so others will know how I feel and what I know. ;-)

I just engaged in a wordy debate with a few guys who were insisting that frequent, regular water changes are absolutely necessary...yet could not explain why.

Well, you were obviously debating with inarticulate people.

They could not give any specifics on what was being altered by the water change, that could not be done in some other fashion.

Dilution is the solution to pollution. Removing some of the polluted water and replacing it with nice clean water is probably the best thing we can do for our fish. It's the way God does it in nature (rain, snow, streams, tides, currents, etc.) and He's been doing things pretty good for a LONG time. ;-) With each PWC (partial water change), you are also removing hormones that cause stunting and health issues for our fish. You are removing DOC's and TDS (dissolved fish poop, etc.... meaning there's diarrhea in your fish tank!). It would be nice if everyone could have daily 100% water changes or even hourly but that's not practical for most folks so a regular and frequent schedule is best. How often and how much depends on the bioload of the tank, the starting water parameters (or tap water baseline - see my blog), the tank's water parameters, etc. If you have a single small fish in a 100G tank, that could probably go months without a PWC. If you have a fully stocked tank or more commonly, an overstocked tank, then PWC's, gravel vacuuming and filter maintenance should be done weekly or even more frequently.

There was some vague talk of "replenishing and renewing" and "electrolytes", but of course you don't "replenish" anything with a generic water change. The only thing you're guaranteed to be adding is H2O, which does not age...and "electrolytes" sounds like a question of specific gravity, to be taken care of with sea salt.

Based on those quotes, it sounds more like you were watching a late night infomercial... are you sure you had a debate and not a dream? LOL Did any of these so-called "guys" suggest using a Sham-Wow to clean the glass?

The actual reason people used to change water regularly was that they were killing their fish with poorly-managed Under-Gravel Filters, and were fighting the nitrate buildup they were causing.

And we still get nitrate buildup... or in a planted tank, we may not get nitrates but we still get DOC's and TDS and decaying plant matter mixed in with any other normal detritus.

But that's no longer the case, thanks to deep sand beds, open-celled ceramic foam, planted tanks, et cetera. There are many ways to remove nitrates so efficiently that they can become TOO low.

Nitrates are... or were... a simple way for us to test our water and IF the nitrates were elevated, we could presume that ALL of the other pollutant levels were elevated... ALL of the other things that we cannot so easily test.. like hormone and pheromone levels, DOC's, TDS' (although some folks might have meters for those), etc. If someone is doing something to lower the nitrates, such as a planted tank, filtration, etc., that may not and probably isn't lowering all of the other pollution levels.

So what reason is left?

See ALL of the above.

What is the reason to do a water change?

See ALL of the above.

And I mean some measurable, explainable reason. Something you can choose to do under specific conditions. Giving a timespan for doing them without reason is meaningless.

See ALL of the above.

Since water changes place stress on fish and ecosystem, by altering the tank's self-imposed balance of micro-organism density, reducing the amount of nutrients, et cetera, water changes were never anything better than a necessary evil.

PWC's SHOULD not place stress on fish. They are done naturally in nature. NOW, if you are waiting too long between doing PWC's, to where your tank's water parameters have degraded to such a point that adding fresh water will change the parameters too much, too fast, then that is what is stressing your fish, not the clean fresh water. For example, if your tap water baseline is 7.5 pH, GH - 10 dH, KH - 7 dH, and you are not keeping up with your tank maintenance so that the water quality has dropped down to 6.0 pH, GH - 2 dH and KH - 2 dH, and then you do a 50% PWC, that would stress the fish's osmoregulatory system by changing their water parameters too much, too fast. In this example, you would have to do a series of smaller PWC's, like 10% PWC's every couple of hours until the tank's water parameters are improving to where you can do a 25% to 50% PWC without causing such drastic water parameter changes.

Are they STILL a necessary evil, and if so, why?

They're not a "necessary evil", BUT RATHER NOT DOING THEM IS PURE EVIL!!!

Here's my blog on doing a Tap Water Baseline.
http://goldlenny.blogspot.com/2007/05/find-your-tap-source-water-baseline.html

 

[GoldLenny]

to add on to what kaz said the water on earth has been reused for about 3 billion years or more. There is no such thing as a global water change. As long as the nutrients necessary for life are there then u do not need to do a wc.

Are you trying to say that our aquariums are competing with God's aquarium? We're not even close. Our closed ecosystems DO NOT have a fraction of the natural things that happen on earth, which results in constant clean water being provided for fish.

Now, if you set up undergrown aquafirs and a full climate system and a rainforest and seasons, etc., then you might be getting closer to the way He does things but until we do that, we have to try and mimic what He does and He does constant and frequent PWC's for His fish. ;-) See my earlier reply for more details.

 

[GoldLenny]

So far, four people have voted that they do water changes on a timeline...

But nobody has posted any explanation as to why.

This sounds, to me, like people are stressing their fish needlessly.

If not, then we need to hear the actual reason for it.

If someone finds that their nitrates build up, in a shallow gravel tank, with such regularity that they can reliably change the water each week, and they don't care to try some better means of reducing nitrates...that at least makes sense. But, really, it falls into the category of "only change when conditions require", because they took the time and effort to learn the schedule of those conditions, in their specific tank.

People who simply change the water every day/week, because someone told them to...is that doing anything but giving the fish needless stress?

To me, it sounds like you are just a little lazy and are trying to justify your attitude of NOT wanting to do PWC's. With every pet and every life form, a certain amount of cleaning and maintenance is required. If you don't want to do the basic and necessary things to sustain that life form, might I suggest you get a pet rock or pet piece of wood or pet piece of plastic??

 

[GoldLenny]

I must admit, I haven't been a fish keeper for long, but I have heard something about WCs help to reduce the concentration of hormones produced by the fish. Is this a myth or could this be a legit reason to refresh tank water?

The balance of life is so complex that there are people that devote their lives to studying how ecosystems work and their dynamics. I think we would be very lucky if we achieved the very perfect balance of -everything- in a fish tank. We are getting close with panted tanks, but, if we're adding something to the tank (food) do we not need to remove this something at another point in the cycle? Or does proper filtration do a good enough job of this?

Filtration is only a temporary storage place for waste.. kind of like your toilet bowl until you flush it. How long do you leave waste in your toilet before flushing it? :yuck:

If you don't do filter maintenance on a frequent basis, that waste dissolves back into the water columen (aka diarrhea). A single fish turd caught by the filter media will completely dissolve back into the water in a day or two, depending on the water flow of the filter. So, unless you are cleaning your filter media every day or two, it's not catching nearly as much as you think. Yes, filter media still catches a lot... but a lot of detritus turns into DOC's (dissolved organic compounds) which is a nice acronym for pollution. Filters should be cleaned at least weekly, which will remove a certain percentage of the fish poop before it dissolves and also remove some of the larger pieces of other undissolved detritus.

Carbon, or other more advanced chemical filtration like Purigen, will help to remove some of the DOC's but not all of them. We don't have any evidence that chemical filtration will remove hormones and/or pheromones, although it might catch some. There are some more advanced filtration being used in the fisheries industry to try and remove the hormones/pheromones but that isn't available to us yet.

Vacuuming the gravel will remove a LOT more of undissolved fish poop since it doesn't dissolve as fast without the filter water flushing over it. Vacuuming the gravel will also remove some potential pathogens and bacteria that might be starting to grow in colony size in dirty funky gravel. PWC's (partial water changes) will also catch some of the water column pathogens before they have a chance to build up to a high enough level to make our fish sick or infested.

 

[GoldLenny]

OK... I think I've made my position clear on how I feel about PWC's! ;-)

 

[Que]

I'd say so.

Q

 

[drgnfrc13]

I see that Kaz was likely a troll and started this thread and then left after 49 replies since he wasn't getting any affirmation for his laziness... but I thought I'd reply to a few of his posts anyhow just so others will know how I feel and what I know. ;-)



Well, you were obviously debating with inarticulate people.



Dilution is the solution to pollution. Removing some of the polluted water and replacing it with nice clean water is probably the best thing we can do for our fish. It's the way God does it in nature (rain, snow, streams, tides, currents, etc.) and He's been doing things pretty good for a LONG time. ;-) With each PWC (partial water change), you are also removing hormones that cause stunting and health issues for our fish. You are removing DOC's and TDS (dissolved fish poop, etc.... meaning there's diarrhea in your fish tank!). It would be nice if everyone could have daily 100% water changes or even hourly but that's not practical for most folks so a regular and frequent schedule is best. How often and how much depends on the bioload of the tank, the starting water parameters (or tap water baseline - see my blog), the tank's water parameters, etc. If you have a single small fish in a 100G tank, that could probably go months without a PWC. If you have a fully stocked tank or more commonly, an overstocked tank, then PWC's, gravel vacuuming and filter maintenance should be done weekly or even more frequently.



Based on those quotes, it sounds more like you were watching a late night infomercial... are you sure you had a debate and not a dream? LOL Did any of these so-called "guys" suggest using a Sham-Wow to clean the glass?



And we still get nitrate buildup... or in a planted tank, we may not get nitrates but we still get DOC's and TDS and decaying plant matter mixed in with any other normal detritus.



Nitrates are... or were... a simple way for us to test our water and IF the nitrates were elevated, we could presume that ALL of the other pollutant levels were elevated... ALL of the other things that we cannot so easily test.. like hormone and pheromone levels, DOC's, TDS' (although some folks might have meters for those), etc. If someone is doing something to lower the nitrates, such as a planted tank, filtration, etc., that may not and probably isn't lowering all of the other pollution levels.



See ALL of the above.



See ALL of the above.



See ALL of the above.



PWC's SHOULD not place stress on fish. They are done naturally in nature. NOW, if you are waiting too long between doing PWC's, to where your tank's water parameters have degraded to such a point that adding fresh water will change the parameters too much, too fast, then that is what is stressing your fish, not the clean fresh water. For example, if your tap water baseline is 7.5 pH, GH - 10 dH, KH - 7 dH, and you are not keeping up with your tank maintenance so that the water quality has dropped down to 6.0 pH, GH - 2 dH and KH - 2 dH, and then you do a 50% PWC, that would stress the fish's osmoregulatory system by changing their water parameters too much, too fast. In this example, you would have to do a series of smaller PWC's, like 10% PWC's every couple of hours until the tank's water parameters are improving to where you can do a 25% to 50% PWC without causing such drastic water parameter changes.



They're not a "necessary evil", BUT RATHER NOT DOING THEM IS PURE EVIL!!!

Here's my blog on doing a Tap Water Baseline.
http://goldlenny.blogspot.com/2007/05/find-your-tap-source-water-baseline.html

Well said.

 

[GoldLenny]

I'd say so.

Q

Thanks. I wasn't sure if I stated my position adequately enough. LOL